yes
Question and rationale: The question is: Have Douglas fir been used to fight wars?
Douglas fir are a type of tree. Douglas fir are used to make ships. The Minesweeper is a small warship made from Douglas fir. The Minesweeper was made of wood to reduce it's risk magnetic signature and likely hood of detonating mines.

yes
Question and rationale: The question is: Does Disney have an ice princess?
In 2013, Disney released Frozen. Frozen features Elsa, a princess with magical ice powers.

no
Question and rationale:
The question is: Does Bombyx mori have a monopoly over silk production?
A monopoly refers to the exclusive supply of a good. The Bombyx mori is a moth famous for its silk production. Spiders, beetles, caterpillars, and fleas produce silk. Wild silk produced by caterpillars has been used in China, Europe, and South Asia since antiquity.